Both are heading for domestic glory - but it is dreams of continental crowns which are intruding on the minds of Sir Alex Ferguson and Pep Guardiola as they bid to steer their teams into the UEFA Champions League semi-finals on Tuesday.
Both Manchester United and Barcelona have one foot in the last four after contrasting first legs - yet both coaches are warning their teams they must take nothing for granted after drawing first blood.
Barcelona, eight points clear in La Liga, thrashed Ukraine's Shakhtar Donetsk 5-1 at the Nou Camp so their passage appears assured - but Guardiola has counselled that injuries and complacency mean they must tread carefully in the return.
Sir Alex meanwhile is only too aware that a 1-0 advantage over Chelsea - even if garnered away from home - does not mean he and his troops can start plotting a potential rematch of a 2009 final lost to the Catalan club.
United, sitting on a seven-point lead over Arsenal in the Premier League - though the Gunners have a game in hand - appear set for domestic glory. A 19th title, and 12th for their long-serving manager, would be an English record, taking the Red Devils ahead of Liverpool. But while United are heading for a hat-trick of Premier League crowns, Ferguson also wants his own Champions League treble after 1999 and 2008 - the second coming at Chelsea's expense.
After Wayne Rooney secured a first win at Stamford Bridge in almost a decade United are cast in the role of favourites - but their manager says they must concentrate on ramming home their advantage. Ferguson rang the changes for Saturday's win over Fulham but complained afterwards that "we were a bit casual and lackadaisical."
He conceded that "at this stage of the season winning is the name of the game" - a philosophy which applies equally to the Chelsea return, even if a draw would suffice.
Chelsea boss Carlo Ancelotti must hope his misfiring £50 million striker Fernando Torres can break his duck at Old Trafford after 648 goalless minutes since arriving from Liverpool. Ancelotti benched Torres for Saturday's win over Wigan but has the luxury of having experienced alternatives in Didier Drogba and Nicolas Anelka.
Chelsea captain John Terry, whose missed penalty in Moscow cost the Londoners a first European crown in Moscow three seasons ago, insists one goal will open the floodgates for the Spaniard. "It's just a case of getting that first goal, getting that off your shoulders, and then you can move on," he said.
Ancelotti was being coy ahead of the game regarding his choice of strike force for a game which could now make or break the Blues' season. "Maybe he will score the most important goal of our season at Old Trafford, who knows. But I do not know who is in the side yet," Ancelotti remarked.
Chelsea did triumph in the league at Old Trafford last season 2-1 and a repeat would send them through - but the impetus appears to be with their rivals, particularly given that only twice in Champions League history has a team prevailed in a knockout tie after losing a first leg match at home. Awaiting the winners will likely be German surprise package Schalke 04, who thumped holders Inter Milan 5-2 at San Siro in their first leg.
Barcelona injury woes
Inter's looming demise with the architect of their win, Jose Mourinho, having moved on to plot Real Madrid's re-ascent to the European summit, will be a boon to Barcelona, meanwhile, as they seek to send Shakhtar packing - before moving on to a probable match-up against Real.
The Italians knocked the Catalan club out in last year's semis, preventing Guardiola's Blaugrana from potentially becoming the first side to reclaim the trophy since the Champions League format was introduced 19 seasons ago. AC Milan were the last club to win the European Cup back to back in 1990.
Barcelona call up Thiago Alcantara, Andreu Fontas and Jonathan dos Santos with Eric Abidal, Carles Puyol and Bojan Krkic all injured, while midfield star Andres Iniesta is suspended. Striker Pedro insisted Sunday that "we will not change the way we play" despite the first-leg lead.